Policy Tags for 5G Network Function Inconsistency Detection and Reconciliation

This application is a continuation of and claims priority to U.S. patent application Ser. No. 18/441,134, titled POLICY TAGS FOR 5G NETWORK FUNCTION INCONSISTENCY DETECTION AND RECONCILIATION, filed on Feb. 14, 2024, which is hereby incorporated by reference in its entirety.

Various embodiments of the present technology generally relate to network function communication within 5G networks. More specifically, embodiments of the present technology relate to systems and methods for providing detecting an inconsistency in shared stated data between two or more network functions (NFs) within a 5G network and reconciling the inconsistency.

In the realm of 5G networks, N7 policy evaluation and decision at the Policy Control Function (PCF) play a pivotal role in ensuring efficient and dynamic network management. N7 represents a reference point in the 5G architecture, specifically designed for communication between the PCF and the Session Management Function (SMF). The PCF is responsible for enforcing policies related to quality of service, network slicing, and user authentication. N7 policy evaluation involves the examination of these policies in real-time, considering factors such as network congestion, user demands, and application requirements. The PCF's decision-making process at the N7 level involves dynamically adapting policies to optimize resource allocation, enhance user experience, and maintain the overall integrity of the 5G network. This capability is crucial for delivering on the promises of low-latency, high-speed connectivity, and personalized services in the era of 5G communications. As technology continues to evolve, the N7 policy evaluation and decision mechanisms at the PCF will remain instrumental in shaping the efficiency and performance of 5G networks.

Currently, to aid in efficient session establishment within the 5G network, the PCF interacts with the SMF. Interactions between the SMF and the PCF are pivotal for orchestrating seamless and optimized user experiences. The SMF takes the lead in session management, handling tasks such as authentication, mobility management, and IP address assignment. Concurrently, the SMF collaborates closely with the PCF to leverage policy information that shapes the characteristics of the user session. The PCF, as the key component for policy control, provides the SMF with real-time policy decisions based on factors like Quality of Service (QOS) requirements, network conditions, and service-level agreements. This interaction ensures that the policies governing aspects such as data prioritization, bandwidth allocation, and application-specific treatment are effectively enforced throughout the user session. Through this dynamic collaboration, the SMF and PCF collectively contribute to the delivery of enhanced 5G services, allowing for adaptive, policy-driven control over network resources to meet the diverse needs of users and applications.

Disruptions, however, may arise leading to the PCF and SMF operating at inconsistent states. As those skilled in the art readily appreciate, operating at an inconsistent state between the PCF and the SMF may lead to disruptions in network performance and user experience. An inconsistent state may result from communication or signaling delays or failures between these key network functions, leading to misalignments in policy enforcement and session management. This miscoordination can trigger discrepancies in QoS, hinder the proper implementation of network slicing, and impact the allocation of resources. Users may experience fluctuations in data speeds, dropped connections, denials, or delays in accessing services. It is imperative for 5G network operators to address and mitigate these issues promptly, as a harmonized and synchronized operation between the PCF and SMF is essential for delivering the promised benefits of 5G, such as low latency, high data rates, and efficient resource utilization.

Currently techniques and systems, however, only allow for reactive detection of inconsistencies between the PCF and SMF. As such, inconsistencies are only detected after they have already occurred and thus often lead to emerging issues. Accordingly, there exists a need for improved signaling mechanisms, such as the policy tags and related functions provided herein, that can provide proactive inconsistency detection and reconciliation between network functions (NFs) within the 5G network. In other words, the policy tags and related functions provided herein can eliminate implicit reactive detection and provide proactive inconsistency detection and reconciliation in many cases.

The information provided in this section is presented as background information and serves only to assist in any understanding of the present disclosure. No determination has been made and no assertion is made as to whether any of the above might be applicable as prior art with regard to the present disclosure.

Technology is disclosed herein for systems and techniques for providing policy tags, and their related functions, to detect and reconcile network function inconsistencies. In particular, policy tags are provided herein for detecting inconsistencies between a NF producer and a NF consumer, such as between the PCF and the SMF. To detect inconsistencies, a policy tag is generated by a NF producer to indicate a current state of operation when communicating with a NF consumer. When the NF consumer receives a policy tag from the NF producer, the NF consumer stores the policy tag. In subsequent communications between the NF producer and the NF consumer, a most recent policy tag is identified and provided to the corresponding NF. For example, when sending an update request to a PCF, the SMF may include a most recent policy tag to indicate its current state. When the PCF receives the update request, the PCF identifies the most recent policy tag and determines its own most recent policy tag (e.g., the policy tag the PCF stored prior to receiving the update request). The PCF then compares the two policy tags to determine if the two NFs are operating according to consistent states.

If a NF producer determines that the two NFs are operating according to a consistent state, then the NF producer continues with the update request. If the NF producer, however, determines that the two NFs are operating according to inconsistent states, then the NF producer determines an inconsistency. As will be described in greater detail below, when the NF producer determines an inconsistency, the NF producer determines an appropriate reconciliation process based on the type of inconsistency and current operational configuration of the NFs. Once the appropriate reconciliation process is identified, the NF producer performs the identified reconciliation process and the two NFs are returned to operating on consistent states.

This Overview is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. It may be understood that this Overview is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Some components or operations may be separated into different blocks or combined into a single block for the purposes of discussion of some of the embodiments of the present technology. Moreover, while the technology is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the technology to the particular embodiments described. On the contrary, the technology is intended to cover all modifications, equivalents, and alternatives falling within the scope of the technology as defined by the appended claims.

The advent of 5G technology represents a paradigm shift in the realm of telecommunications, promising unprecedented advancements in connectivity, speed, and reliability. Unlike its predecessors, 5G is characterized not only by enhanced data rates but also by low latency, massive device connectivity, and the ability to support diverse applications, ranging from augmented reality to the Internet of Things (IoT). At the heart of the 5G architecture is the Service-Based Architecture (SBA), which fundamentally transforms the way network functions operate. In the 5G ecosystem, various network functions (NFs) are modularized, each serving specific roles in delivering end-to-end services. These NFs, including the Session Management Function (SMF), Policy Control Function (PCF), User Plane Function (UPF), and others, are interconnected through standardized interfaces, allowing for a more dynamic, scalable, and flexible network. The SBA enables these NFs to act as producers and consumers of services, fostering a modular and interoperable environment where services are orchestrated seamlessly to meet the diverse needs of users and applications. This architectural evolution is pivotal in realizing the full potential of 5G networks and accommodating the demands of an increasingly connected and data-driven world.

However, despite the promise of 5G's advanced capabilities, the presence of inconsistencies between NFs can significantly undermine the performance and reliability of the network. In a 5G ecosystem where NFs operate collaboratively, any misalignment or inconsistency in communication between these functions may result in suboptimal service delivery. Issues such as misconfigured policies, conflicting QoS parameters, or delays in data transmission between functions can lead to service disruptions, degraded user experiences, and compromised network efficiency. For instance, if the SMF fails to synchronize seamlessly with the PCF, it may lead to discrepancies in policy enforcement, affecting crucial aspects like traffic steering and resource allocation. The interconnected nature of these NFs demands a harmonized operation, and any inconsistencies introduce vulnerabilities that can impede the seamless connectivity and advanced functionalities promised by 5G technology.

One area in which inconsistencies adversely impact the functionality of 5G technology is communication between the SMF and PCF. Inconsistencies between the SMF and the PCF can have profound consequences on the 5G network and a user's experience within the 5G network. For example, when SMF-PCF inconsistencies occur, critical policies governing QoS, network slicing, and user authentication may not be uniformly enforced, leading to variations in service delivery. That is, if the SMF and PCF fail to communicate seamlessly, it may result in inaccuracies in policy decisions, impacting data prioritization, bandwidth allocation, and overall traffic management. Inconsistent enforcement of policies may disrupt the promised low-latency communication, compromise user data security, and hinder the efficient utilization of network resources. Furthermore, these discrepancies can pose challenges in implementing dynamic services and adapting to changing network conditions.

Adding another layer of complexity to the challenges posed by SMF-PCF inconsistencies is the fact that the PCF, in its current design, often lacks the capability to proactively detect such inconsistencies. The PCF relies heavily on the information provided by various NFs, including the SMF, and inconsistencies may arise due to factors such as communication delays, configuration errors, or unforeseen network events. The reactive nature of inconsistency detection in the PCF can result in delayed responses to emerging issues, leaving the network vulnerable to disruptions. As a consequence, potential inconsistencies may only be identified when they manifest as operational problems or user experience issues, making it challenging to implement preemptive measures. Establishing mechanisms for more proactive monitoring, early detection, and automated resolution of inconsistencies between the SMF and PCF is crucial for enhancing the resilience and reliability of 5G networks in the face of dynamic and evolving communication environments.

To allow for proactive inconsistency detection between the PCF and SMF, example policy tags and their related functions are provided herein. The policy tags are generated by a NF producer to indicate the current state of operation. A state of operation for a network function, such as the PCF or SMF, encompasses the specific configuration, resource allocation, and rule sets that dictate its current mode of functionality within the broader network ecosystem. Thus, when communicating with a NF consumer, a NF producer generates and provides a policy tag to indicate the NF producer's current operating state. For example, the NF producer may receive a request from an NF consumer to establish a session. The session request may include state data for the session. Responsive to receiving the session request, the NF producer generates a policy tag for the session and stores the policy tag along with the state data for the session. The NF producer also transmits the policy tag to the NF consumer for the NF consumer to store and use in future communications. Thus, when the NF consumer communicates with the NF producer at a future time, the NF consumer provides the stored policy tag along with its request or response, thereby providing information as to its current operating state.

Carrying forward, whenever there is an update in state by either the NF consumer or the NF producer, a new policy tag is generated and used for subsequent communications. In this manner, each NF can provide information on its current state to its NF counterpart, thereby allowing for identification of inconsistencies. By identifying inconsistencies before implementing a new operating state, one or more reconciliation methods can be performed to rectify the inconsistency. For example, when the NF producer receives the policy tag from the NF consumer, the NF producer compares that policy tag against a respective stored policy tag. If the received policy tag matches the respective stored policy tag, the NF producer validates that both NFs are operating at the same state. If, however, the NF producer determines that the policy tag received from the NF consumer does not match the respective stored policy tag, then the NF producer identifies the inconsistency between the two NFs and can determine an appropriate reconciliation method. A reconciliation method may be determined by the NF producer based on a type of conflict and operation configuration. Example reconciliation methods include last-update-wins, termination of the session and re-establishment of a new session, merging of the session records, re-synchronization of session states, and rebuilding of the session state. Each of these types or reconciliation methods will be described in greater detail below.

The policy tags and related functions provided herein allow for timely identification of inconsistencies between NFs. Timely identification of inconsistencies between these functions is essential to prevent potential disruptions, enhance network reliability, and optimize resource utilization. The proactive detection provided by policy tags allows network operators to address discrepancies before they escalate into critical issues, ensuring that policies are applied consistently across sessions. As such, policy tags and their related functions not only safeguard the integrity of service delivery but also promote the effective implementation of QoS parameters, enabling 5G networks to meet the diverse and evolving needs of users and applications. In summary, policy tags provide for proactive detection and reconciliation of inconsistencies between PCF and SMF, thereby maintaining a resilient and high-performing 5G network.

It should be appreciated that while the following discussion involves the NF producer and NF consumer being one of the PCF and the SMF, the policy tag and its related functions are equally applicable for other NFs. However, for ease of discussion the example policy tags provided herein are described in the context of the N7 level communication between the PCF and the SMF.

Turning now to the Figures,illustrates an example operational environment for a 5G networkin which one or more features of a policy tag process can be implemented, according to an embodiment herein. The example 5G networkis a 5G core (5GC) cellular network implementing 3GPP (3rd Generation Partnership Project) communication standards, although the present disclosure may apply to other communication networks.

The 5G network, its components, and their sub-components may be implemented via computers, servers, hardware and software modules, or other system components. The components of the 5G networkand its subcomponents, or the physical devices implementing them, may be co-located, remotely distributed, or any combination thereof. The elements of 5G networkmay include components hosted or situated in the cloud and implemented as software modules potentially distributed across one or more server devices or other physical components.

The 5G networkis divided into two fundamental planes: a control planeand a user plane, each serving distinct yet interdependent roles. The control planeis responsible for managing the signaling and control information necessary to establish, modify, and terminate communication sessions. The control planehandles tasks such as authentication, policy enforcement, and mobility management. As such, the control planeis crucial for orchestrating and controlling the NFs, ensuring efficient and secure connectivity. On the other hand, the user planedeals with the actual data transmission—the movement of user data between devices and applications. It is optimized for high-throughput, low-latency data delivery, and is designed to efficiently transport user traffic. The separation of the control planeand user planein the 5G networkenhances scalability, flexibility, and enables network slicing, allowing tailored configurations to meet diverse service requirements. Together, these planesandform a cohesive architecture that empowers the 5G networkto deliver unprecedented speed, reliability, and versatility for a wide array of applications and services.

As noted above, the user planeof the 5G networkoperates in tandem with the control planeto deliver efficient and seamless data transmission. For example, as illustrated, when a User Equipment (UE), which could be a smartphone or any other device, initiates a communication the user planehandles the actual user data traffic. When the UEinitiates communication, the Radio Access Network (RAN)comes into play, managing the wireless connection between the UEand the network, in particular the UEand the Access and Mobility Management Function (AMF). The RANacts as the bridge between the user planeand the control plane, facilitating the establishment of communication sessions. As data travels through the RAN, it encounters the User Data Function (UDF), which plays a pivotal role in processing and optimizing user data. The UDFis responsible for tasks such as traffic optimization, content caching, and data transformation, enhancing the efficiency of data delivery.

The UDFprovides the data to the Data Network (DN), which could represent the broader internet or a specific network service. The DNprocesses and delivers the user data to its intended destination, completing the journey initiated by the UE. The collaborative operation of the user plane, UE, RAN, UDF, and DNensures that data is transmitted reliably and efficiently, meeting the high-performance expectations of 5G networks. As those skilled in the art readily appreciate, the separation of user planeand control planeallows for flexible network configurations and optimizations, contributing to the enhanced capabilities of the 5G ecosystem.

As noted above, when the UEinitiates a communication within the 5G network, the AMFcoordinates the interaction. For example, when the UEinitiates communication or moves within the 5G network, it sends signaling messages to the AMF. The AMFis responsible for tasks such as authentication, authorization, and mobility management. Upon receiving the signaling messages from the UE, the AMFvalidates the user's identity, checks for necessary permissions, and establishes the necessary context for the session. The AMFcoordinates with other network functions, such as the Session Management Function (SMF)and the User Plane Function (UPF), to ensure the seamless setup and management of communication sessions. The interaction with the control planeenables the UEto access network services, adhere to established policies, and maintain continuous connectivity while benefiting from the advanced capabilities and optimizations offered by the 5G network architecture.

The control planeincludes example components, nodes, or NFs. As illustrated, the control planeincludes the AMF, the SMF, the UPF, an Authentication Server Function (AUSF), a Network Slice-Specific Authentication and Authorization Function (NSSAAF), Service Communications Proxy (SCP), a Network Slice Selection Function (NSSF), Network Exposure Function (NEF), a Network Repository Function or NF Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), and an Application Function (AF). The selection of NFs-depicted in the 5G networkis exemplary, and some of the NFs-may be excluded, or other NFs added to the collection, without departing from the scope of this disclosure. The various NFs-execute various operations to provide communication services to UEs, such as the UE, that connects to the 5G network. A network node or NF that provides service is referred to herein as a NF producer, while a network node or NF that consumes services is referred herein to as a NF consumer. A network function can be both a NF producer and a NF consumer depending on whether it is consuming or providing service.

The NFs-of the 5G networkexchange various communications in the course of providing network services. The communications may include messaging to establish or end secured communication channels, such as transport layer security (TLS) handshakes, as well as service-based interface (SBI) communications. As used herein, SBI is the term given to the application programming interface (API) based communication that can take place between two NFs within the 5G SBA. A given NF can utilize an API call over the SBI to invoke a particular service or service operation. Communications between NFs-may be performed over network links and communication channels of the 5G networkthat are not explicitly depicted in.

When the UEinitiates communication within the 5G network, the PCFand the SMFwork collaboratively to ensure a seamless and optimized user experience. When the UEinitiates a communication session, the UEsends signaling messages to the SMFindicating the intent to establish a communication session. The SMFthen engages with the PCFto enforce policies relevant to the specific user, application, or service. The PCFis responsible for policy decision-making and evaluates the communication request based on predetermined policies, network conditions, and user profiles. The PCFcommunicates with the SMFto convey policy decisions, which are then implemented to control aspects such as QoS, traffic steering, and resource allocation. This dynamic interaction between the PCFand SMFis integral to providing a tailored and efficient communication experience, ensuring that policies are applied consistently across the session, and facilitating the network's ability to adapt to varying user and application requirements in real-time.

Miscoordination between the SMFand the PCF, however, does occur. For example, miscoordination can arise when there are disruptions in the communication and data exchange between the SMFand the PCF. Factors such as network latency, data transmission errors, or software glitches can contribute to misalignment, leading to inconsistencies in policy decisions and session management. These disruptions can result in suboptimal QoS, inefficient resource utilization, and an overall compromise in the coherent application of policies between the PCFand the SMF.

Turning now to, exemplary miscoordination scenarios that result in SMF-PCF inconsistencies are illustrated. Starting with, an example SMF-PCF inconsistency scenariois illustrated, according to an embodiment herein. As illustrated, the scenarioinvolves a SMFand a PCF, which may be the same or similar to the SMFand the PCFwithin the 5G network. As such, the SMFand the PCFwork collaboratively to establish and maintain a communication session for a respective UE, such as the UE, within the 5G network. In the illustrated example, the SMFis the NF consumer and the PCFis the NF producer.

When a UE initiates a communication session, the SMFtransmits a session requestto the PCF, such as an “Npcf_SMPolicyControl_Create” request. The session requestinitiates the establishment of a communication session within the 5G network between the UE and respective end point. The session requestincludes pertinent information for establishing the session, such as QoS requirements, user authentication details, and application-specific parameters. In other words, the session requestincludes state data that enables the PCFto make informed policy decisions and orchestrate a tailored session that meets the specific needs of the UE and associated services.

When the PCFreceives the session request, the PCFestablishes a communication session at a first statebased off of the state data provided in the session request. Once the session at the first stateis established, the PCFtransmits a communicationto the SMF, such as a response including a “—Created” HTTP response code. The communicationtypically includes details about the approved policies, QoS parameters, and any specific conditions or constraints associated with the first stateof the session as established. As those skilled in the art readily appreciate, the communicationenables the SMFto synchronize its session management functions with the policies set by the PCF, ensuring consistent and optimized control over the communication session throughout its duration. As illustrated, upon receipt of the communication, the SMFbegins operating according to the policies, QoS parameters, and the like of the first state.

At some later point, the SMFtransmits a communication, such as an update, to the PCF. The updatemay be a Policy Control Update Request that includes information relating to the communication session that requires an update in policies or QoS parameters. The updatemay encompass details such as change in bandwidth requirements, priority levels, latency constraints, or other attributes associated with the user's session. Upon receipt of the update, the PCFprocesses the updateto dynamically adapt and enforce policies based on the evolving needs of the session, ensuring a responsive and tailored network experience for the UE and associated services. In other words, when the PCFreceives the update, the state of the communication session is updated from the first stateto a second state. Once the second stateis implemented, the PCFtransmits the state data in a communicationto the SMF, for example as part of a “—OK” HTTP status response message. Once the SMFreceives the communication, the SMFupdates to the second state. As used herein, the term “communication” may encompass any exchange between an NF consumer, here the SMF, and a NF producer, here the PCF. For example, a communication between these two NFs includes any internal exchanges (e.g., policy rule change by operator) or external exchanges (Rx/N7 request for corresponding N7 session or UDR/CFH notifications).

At another later point, the SMFmay transmit a second communication, such as a second update. Since the SMFrequests updates when the conditions or requirements of the ongoing communication session change, it can be appreciated that the SMFmay transmit numerous updatesandduring a given communication session. Similar to above, when the PCFreceives the second update, the PCFprocesses the update and modifies the session accordingly, here by updating from the second stateto a third state.

Once the third stateof the session is established, the PCFtransmits a communication, which includes the associated state data for the third state, to the SMFso that the SMFcan update its state to match the third state. Here, however, there is a disruption that causes the communicationto not be received by the SMF. Network congestion or latency, resource constraints, or communication errors may result in a timeout, and the PCFwill have no indication that the SMFdid not receive the communication. While in some cases, the timeoutmay trigger an error handling mechanism or procedure designed to manage the situation, prior to any resolution of the timeout, the communication session continues in a state where the SMFis operating according to the second stateand the PCFis operating according to the third state.

The SMFmay send a subsequent communicationat a later point. However, because the PCFand the SMFare operating at two different states, the PCFmay not be able to process the communicationcorrectly or at all. As noted above, operating in inconsistent states can lead to a variety of negative consequences for a given communication session. That is, the SMF-PCF inconsistency depicted in the scenariomay result in misaligned policy enforcement, leading to suboptimal resource utilization, compromised user experience, and an increased risk of service disruptions or inefficiencies in the dynamic orchestration of network functions.

The SMF-PCF inconsistency may be further exacerbated by the PCFreceiving a notification. The notificationmay be an Rx request, UDR notification, or a Chf notification. The notificationmay be received from another NF, such as the AF, and may include an update to various policies or QoS parameters for the communication session. Responsive to receiving the notification, the PCFtransmits a communication, such as an update notify, to the SMF. The update notifymay notify the SMFabout changes in policies or conditions relating to the ongoing communication session. For example, the update notifymay include updates to the QoS parameters, changes in access control policies, or any other information that the SMFneeds to be aware of to adapt its management of the session accordingly. The SMF, however, is unable to appropriately process the update notifyto achieve the correct state because the SMFis operating according to the second state. Again, such an SMF-PCF inconsistency can result in a variety of adverse consequences.

Turning now to, another example SMF-PCF inconsistency scenarioinvolving multiple PCFs is illustrated, according to an embodiment herein. As shown, the scenarioinvolves a SMF, a first PCFA, and a second PCFB. The SMFmay be the same or similar to the SMF, and the first and second PCFsA andB may be the same or similar to the PCFoperating within the 5G network. As such, the SMFmay transmit a requestto the first PCFA to establish a communication session. The requestmay be similar to the requestand include state data containing various information needed to establish the session.

Responsive to receiving the request, the first PCFA establishes the communication session in a first state. Then the PCFA transmits a communicationto the SMFcontaining state information associated with the first state. Upon receipt, the SMFmanages the communication session according to the first state.

Simultaneously or shortly after establishing the first statefor the session, the first PCFA performs data replicationof the first stateto the second PCFB. The replicationof the state data associated with the first statefrom a first PCFA to the second PCFB serves as a critical mechanism to enhance the reliability, availability, and overall performance of a 5G network. For example, data replicationensures high availability by providing a seamless failover mechanism; in the event of the first PCFA failure, the second PCFB can seamlessly take over, preventing service disruptions. Additionally, data replicationsupports load balancing, allowing for efficient distribution of processing tasks between PCFsA andB, thereby optimizing resource utilization and accommodating varying workloads. Once the second PCFB receives the data replication, the second PCFB stores the first state dataand begins operating accordingly.

At some point, the SMFtransmits an updateto the first PCFA. Responsive to receiving the update, the first PCFA updates to a second stateand transmits a communicationback to the SMF. Similar to or the same as the communication, the communicationcontains state data associated with the second statesuch that when the SMFreceives the communication, the SMFmanages the session according to the second state.

As illustrated, the first PCFA performs data replicationto replicate the state data associated with the second stateto the second PCFB. However, before the second PCFB receives and processes the data replication, the second PCFB receives a notification. As can be appreciated, network congestion, communication errors, resource constraints, and the like may cause delayed receipt of the data replicationby the second PCFB. In another example, the notificationmay be transmitted to the second PCFB prior or simultaneous to the data replicationsuch that the second PCFB receives notificationbefore the data replication.

Responsive to receiving the notification, the second PCFB transmits an update notifyto the SMF. Upon receiving the update notify, the SMFimplements a third stateaccording to the update notifyand transmits a responseto the second PCFB. When the second PCFB receives the responsefrom the SMF, the second PCFB implements the third state data, as confirmed by the response.

When the second PCFB implements the third state data, however, the responseis applied to the second PCFB's current state, which is the first state, not the second statethat the SMFis working on. As such, when the second PCFB updates its current state based on the third state data, a third prime stateis generated. As can be appreciated, depending on what state the notificationwas intended to apply to, application of the responseto the first state, instead of the second state, is likely to result in a mismatch between the SMFand the second PCFB. The mismatch is further exacerbated by the second PCFB performing data duplicationof the third prime stateto the first PCFA. Now both the first and second PCFsA andB are running on inconsistent states from the SMF.

As is illustrated by the simplistic depiction of scenario, one or more NFs can be operating according to inconsistent states in a minimal number of actions. Accordingly, it is advantageous to proactively identify and reconcile any misalignments or inconsistencies in operating states between NFs, such as the SMF, the first PCFA, and the second PCFB.

Turning now to, example policy tags and related functions are described for proactively detecting and reconciling inconsistencies between two or more NFs. Starting with,provides an operational scenarioillustrating use of policy tags between an NF producer and an NF consumer, according to an embodiment herein.is described in tandem withfor illustrative purposes.illustrates a processfor proactively detecting and reconciling inconsistencies between two or more NFs using policy tags, according to an embodiment herein. For ease of discussion, the processis referred to herein as the policy tag process. Additionally, it should be appreciated that while the processis described with reference to, that one or more steps of the processis equally applicable to any other Figure or component within a Figure provided herein.

With reference to, the operational scenarioincludes two NFs, one of which operates as a NF consumer and the other operates as a NF producer. In the illustrated example, the NF consumer is a SMFand the NF producer is a PCF, which may be the same or similar to the SMFand the PCF, respectively. As such, the SMFand the PCFare communicatively coupled to exchange communications or messages within a 5G network, such as the 5G network.

At some point, the SMFtransmits a session requestto the PCFto establish a session. Upon receipt of the request, the PCFestablishes the session according to state data present within the request. In particular, the PCFestablishes a first statefor the session (). As part of or subsequent to establishing the first state, the PCFgeneratesa first policy tag (s) for the first state() and stores () the first policy tag (s) along with the corresponding state data for the first state (). When the PCFstores () the first policy tag (s), it is referred to herein as the first stored policy tag (s). The first stored policy tag (s) may be stored in a database (DB) associated with the PCF.

As described above, policy tags, such as the first policy tag (s), provide a means for detecting inconsistencies between a NF producer, here the PCF, and a NF consumer, here the SMF. To detect inconsistencies, policy tags include an opaque identifier that is assigned by a server or by the NF producer, here the PCF, and indicates a specific version of a resource. The opaque identifier is opaque in that a UE or client is unaware of how each policy tag is constructed or even of the policy tag's inclusion within a communication. As such, the inclusion of the policy tag is evident only to the receiving NF consumer, here the SMF.

The opaque identifier of the first policy tag (s) includes information relating to a specific version of a resource or state of the session. In the illustrated example, the opaque identifier of the first policy tag (s) includes a site identifier (ID) and a timestamp. The site ID for the first policy tag is “s” and the timestamp is “t.” In some cases, a site ID refers to an NF Instance ID (e.g., “nfInstanceID”) provided by a respective NF. Although the following illustrative examples include a site ID and a timestamp in this format, those skilled in the art should readily appreciate that variations in nomenclature and format are equally contemplated herein. Additionally, variations in information included in the policy tag are also contemplated herein.